I have tried a few, and frankly they all seem to have pros and cons. :)
Frogbit didn't like my tank, or my light, and just went yellow, one leaf at a time, getting smaller and smaller. I was forever tidying up after it. I think part of the problem may have been the amount of current I have, which caused them to bump about a bit. But I would rather have surface movement than frogbit.
Elodea melts on me. Every time.
Riccia Fluitans is fab - grows well, looks fantastic, my bettas LOVE draping themselves over it, and hovering under it. Except for one teensy little problem - it is made up of thousands of tiny, unconnected strands, and the moment you do a water change, or tweak the tank, those strands break off and snag on other plants and ornaments and start growing there - leading to Riccia outbreaks everywhere. If you have any other moss in the tank, the Riccia will use it as a nice growing medium. lol. I now remove the entire riccia mat before touching anything in the tank, and then put it back afterwards. It would be brilliant for raising fry.
Watersprite is lovely. Eats up nitrates like a hungry elephant. Grows spectacularly and needs pruning with every water change. Love it. Except for the knotty central clumps that grow multiple thick stems and great fuzzball roots. The roots are yellow brown, and start to look dirty, and the light gets obscured. I only use it in a tank where I want masses of surface cover, dim light AND am happy to remove the old growth once a week.
Hornwort is my current favourite, but I prefer the tougher variety (which is more difficult to source). It also doubles in size in a week, but it easier to prune, and easier for my fish to swim through. No untidy roots, and doesn't block the light int he same way. Looks lovely, with its fine, lacey strands.
Having had duckweed sneak in on other plants, and then try to take over the tank, I remove it whenever I see it, but it is really difficult to eradicate, especially if there are other floating plants in the tank.
: 70litre mature setup; betta, purple rasboras, 2 nerites, amano and wood shrimp. Heavily planted.
: 22litre cube; betta, 2 amano. Heavily planted.
: 57litre cube; betta, ember tetras, 2 amano, 1 nerite, heavily planted.
; honey gourami, cherry barbs, green neons, kuhli loaches, otocinclus, pond snails and 1 assassin doing his thing. Heavily planted.